AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
Soot Formation Models for Non-Premixed Flames with Variable Stoichiometric Mixture Fraction and Strain
PHILLIP JOHNSON, Rajan K. Chakrabarty, Benjamin M. Kumfer, Washington University in St. Louis
Abstract Number: 395 Working Group: Combustion
Abstract Many soot formation models were developed for a particular application with unique characteristic mixing times and/or validated under fuel-air combustion conditions only. Therefore, their use in different contexts, such as oxy-combustion, can lead to inaccurate predictions. A soot-producing flame can become non-sooting (blue) with an increase in Zst, even while maintaining constant flame temperature, or through increasing strain rate. In this study, twelve semi-empirical soot models were evaluated on their ability to respond to changes in Zst and strain in a series of counterflow flames which span the experimental sooting-to-non-sooting transition.
All current semi-empirical models failed to predict a blue flame for increased Zst. Two current semi-empirical models predicted a blue flame for increased strain. No existing model came within an order of magnitude of its predicted soot volume fraction target for both evaluations. A new semi-empirical model that is currently in development was also evaluated which uses only one equation and does not require complex gas chemistry. Despite its simplicity, preliminary results show that this model was able to predict a blue flame for both evaluations.